TT Tribal Mephisto: 3576. The Tribal came out in something like '99-ish and was only produced for less than a year (again, if I'm remembering correctly) so none of those numbers really correlate to a date. But I can easily see a production run of over 3,500.

Doc.

To add to this, it seems to be widely accepted that no Tribal serials under 1000 or over 4000 were produced. It seems like there were less than 3000 of them made. And there doesn't seem to be any correlation between milling type (BBT, Twister, Mephisto, Addicted, Fluster) and serial number.

EDIT: I have BBT S/N 1937, no idea as to build date. It has header pins for the solenoid rather than socket pins, this seems to place it as 1.0 as opposed to 2.1 or 2.1, so it would have been early in the production run, assuming the solenoid wasn't swapped at some point.